Anticavitation plate for outboard motors



Nov. 5, 1929. D. w. KING ET AL 'LNTICAVITATION PLATE FOR OUTBOARD MOTORS Filed July 5, I928 Dan HZKing and firfbUrLLaakzzmad 7 attozmu a 40 ment to the transom 4 of a boat.

Patented Nov. 5, 1929 UNITED STATES PATENT OFFICE.

DON W. KING AND ARTHUR L. LOCKWOOD, OF JACKSON, MICRIGAN, ASSIGNORS, BY

MESNE ASSIGNMENTS, TO OUTBOARD MOTORS CORPORATION, OF DETROIT, MICHI- GAN, A. CORPORATION OF MICHIGAN ANTICAVITATION TLATE FOR OUTROARD MOTORS Application med July 5, 1928. Serial No. 290,308.

The present invention pertains to a novel anti-cavitation plate for outboard motors, and the principal object is to cause the exhaust of the motor to be discharged through 5 the plate. Such a construction results in quiet operation due to under water exhaust, reduction of exhaust back pressure due to the ejector action of the plate moving through the water, decreased drag of the plate through the water by relieving the suction behind its trailing edge, and reduction of the volume of the exhaust gas due to the cooling efi'ect of the large surfaces of the plate in contact with the water. A r The invention is realized essentially by forming the anti-cavitation plate with a mouth in the rear or trailing edge thereof and connecting this plate to the usual exhaust pipe of the motor. The mouth preferably flares outwardly from its point of connection with the exhaust line, in order to pro vide for quick expansion and discharge of the exhaust gas therefrom.

The invention is fully disclosed by way of example in the following description and in the accompanying drawing, in which- Figure 1 is a vertical elevation of an out board motor equipped withthe invention and applied to a boat; and Fig. 2 is a sectional view of the anti-cavitation plate on the line 22 of Figure 1.

Reference to these views will now be made by use of like characters which are employed to gdesignate corresponding parts through- The numeral 1 indicates in general the usual motor structure which has a swivel connection 2 to a clamp 3 adapted for attach- The adjustments of this assembly are conventional an therefore neednot he described.

At the lower end of the otor structure is the usual propellor shaft housing 5 on which is formed an anti-cavitation plate 6, preferably as an integral of ovoid cross section.

The rear or trailing end of the plate is formed with a mouth 7 beneath its upper and lower surfaces. The mouth is rather narrow at a point substantially coinciding with the center of the plate and flares outwardly and rearwardly as clearly shown in Figure 2. A pipe 8 connects the narrow or restricted portion of the mouth to the usual exhaust outlet of the motor as "shown in Figure 1. V r

The exhaust-gases are therefore conducted through the pipe 8 to the mouth from which they are discharged under water. The exhaustnoise is therefore mufiled, the volume of the exhaust gases are reduced by the large areas of the plate in contact with the water, and the above mentioned pressure conditions at the rear of the plate are realized.

Although a specific embodiment of the invention has been illustrated and described it will be understood thatvarious alterations in the details of, construction may be made without departing from the scope of the invention as indicated by the appended claims.

What we claim is I 1. In an outboard motor construction, an anti-cavitation plate adapted for submersion, a mouth in said plate, and an exhaust pipe from said motor connected to said mouth.

2. I11 an outboard motor construction, an anti-cavitation late adapted for submersion, an outwardly flaring mouth in said plate,

and an exhaust pipe from said motor connected to said mouth. 3. In an outboard motor construction, a propeller shaft housing, an anti-cavitation plate formed integral with said housing, a' mouth in said plate, and an exhaust pipe from said motor connected to said mouth.

4. In an outboard motor construction, a,

part of the housing and I an exhaust pipe from said motor connected to said mouth.

5. In an outboard motor construction, an anti-cavitation plate adapted for submersion,

' a mouth at the rear or trailing end of said plate, and an exhaust pipe from said motor connected to said mouth.

6.111 an outboard motor construction, an anti-cavitation plate adapted for submersion, a mouth atthe rear or. trailingend of said plate, and flaring outwardly, and an exhaust Y pipe from said motor connected to said mouth.

In testimony whereof we affix our signatures.

DON W. KING. ARTHUR L. LUCKWUOD. 

